(a) Field of the Invention
The invention relates to a metal core printed circuit board and an electronic package structure, particularly to a metal core printed circuit board and an electronic package structure having better heat dissipation.
(b) Description of the Related Art
FIG. 1 shows a DC-to-DC converter package according to the prior art. As shown in FIG. 1, the DC-to-DC converter package is disclosed in U.S. Pat. No. 6,212,086. DC-to-DC converter package 100 comprises circuit board 120, copper plate 110 and a plurality of electronic components. Copper plate 110 is clad to the bottom surface of circuit board 120 and thus allows heat to be approximately equally distributed over the bottom of the package. The electronic components include main transformer 130, output inductor 140, synchronous rectifier 150, output capacitor 160 and input capacitor 170, and are disposed on circuit board 120 so that the electronic components may be coupled to each other through the circuit layout inside circuit board 120. One stand-alone output connector is disposed on the right-hand side of circuit board 120 and coupled to circuit board 120 through a flexible printed circuit board. The disadvantage of this prior art is that circuit board 120 is not a good heat sink and cannot efficiently dissipate heat generated by electronic components 130, 140, 150, 160 and 170 thereon to copper plate 110. The use of circuit board 120 would make it easy to allocate the circuit layout but make it difficult to dissipate heat. On the contrary, the use of copper plate 110 would make it difficult to allocate the circuit layout but make it easy to dissipate heat. It is urged by those who are skilled in the art to develop one substrate having both advantages of easy circuit allocation and heat dissipation.